A fuse block assembly provides a receptacle for one or more fuse elements. Each assembly comprises a fuse block having one or more fuse-receiving cavities and one or more removeable fuse caps which engage with the cavities. The required electrical connection of each fuse element between a power source and protected circuitry is provided by an electrical contact structure in each cap and fuse-receiving cavity. This contact structure is spring loaded to maintain the required connections under rather severe environmental conditions.
In telecommunications applications, it is also necessary to provide each fuse mounting position with the ability to activate alarm circuitry when the retained fusible element overloads or "blows". Furthermore, since multiple numbers of mounting positions are often disposed in close proximity to one another, it is also desirable that visual indication of the particular "blown" fuse be provided. Such an indication substantially reduces the time to locate the problem and restore the protected circuitry to service.
A fuse block assembly providing all of the above-described capabilities is disclosed in U.S. Pat. No. 3,299,236 to T. H. Barker, issued Jan. 17, 1967. The problem with the referenced assembly is that it is not readily repairable in the field. In particular, the electrical terminal structure within each fuse block cavity, which is the most failure-prone assembly component, cannot be replaced without complete fuse block replacement. Such replacement is time consuming and on multiple fuse block assemblies necessitates disconnecting large numbers of functioning circuits. In addition, the disclosed design requires an expensive manufacturing procedure.